Photographic triorganophosphine-azide dye forming composition and article

ABSTRACT

Photographic compositions including a radiation-sensitive complex of a triorganophosphine, e.g. a triarylphosphine, with an organoazide such as an arylazide are radiation-sensitive and can be imagewise exposed to activating rays to yield a species that can react with a dye-forming coupler to form an image dye, e.g. an azo dye. Optionally, such compositions can include a polymeric binder and/or a dye-forming coupler. In another aspect, imageforming compositions are presented which include the organoazide and a precursor to the triorganophosphine, a phosphonium salt for example, that yields triorganophosphine on treatment with base. With such an embodiment, the composition is relatively lightinsensitive prior to alkaline treatment which activates the composition by forming the phosphine-azide complex in situ, and shelf life is desirably extended. When these compositions are present on a support, photographic or image-forming elements are formed. Once the azide-phosphine complex is present in a composition or element of this invention, imagewise exposure to activating rays for the complex and subsequent or concomitant treatment with a dye-forming coupler or the like produces a photographic image in exposed regions, i.e. a negative image of the original exposure. If a leuco compound, dye forming coupler, etc., is present in the composition, then a visible image generally forms on exposure. After production of the image, it can be stabilized by overall heating. In certain cases, heat fixation also produces intensification of a low density or substantially latent photographic image. If desired, positive images can be formed by thermophotographic means. Once the phosphineazide complex is present in the composition, imagewise exposure to heat desensitizes the complex in heated regions and a subsequent overall exposure to activating rays for the complex produces either a visible or an intensifiable photographic image. No heat fixation is required, but image intensification can be accomplished by heat. Lithographic printing surfaces can be prepared when a hydrophilic polymeric azide is used to form the phosphine azide complex or when hydrophilic polymeric couplers are used to form the dye image.

United States Patent [1 1 Grisdale et al.

[ 1 PnoToGRAPIIIC TRIORGANOPHOSPHINE-AZIDE DYE FORMING COMPOSITION AND ARTICLE [75] Inventors: Patrick J. Grisdale; Bruce E. Babb,

both of Rochester, N.Y.

[73] Assignee: Eastman Kodak Company,

Rochester, N.Y.

22 Filed: Aug. 2, 1971 21 Appl. No.: 168,392

[52} US. Cl"... 96/91 N, 96/33, 96/35.1, 96/36, 96/48 HD, 96/49, 96/75, 96/90 R,

[51] Int. Cl. G03c 1/52, G03c 1/58, G030 H72 [58] Field of Search 96/91 N, 90 R, 115 R, 96/115 F, 75, 33, 35.1, 36; 260/349 [5 6] References Cited UNITED STATES PATENTS 3,062,650 II/1962 Sogura et al 96/91 N 3,598,585 8/1971 Gaspar 96/91 N 3,275,443 9/1966 Wainer 96/90 R 3,282,693 l1/1966 Sagura et al. '96/91 N X 3,374,094 3/1968 Wainer et al. 90/90 R X 3,475,176 10/1969 Rauner 96/35.I X 3,660,093 5/1972 Ranz et al 96/91 N 3,331,761 7/1967 Mao 204/159.23 3,594,170 7/1971 Broyde 204/159.24

. OTHER PUBLICATIONS Van Allan et al., Journal of-Heterocyclic Chemistry, Vol. 5, 1968, p. 471-476. 1 Leffler et al., Journal of Organic Chemistry, Vol. 26, 1961, p. 4,810-4,8l4.

Primary Examiner-Charles L. Bowers, Jr. Attorney-Robert W. Hampton et al.

[57] ABSTRACT Photographic compositions including a radiationsensitivecomplex of a triorganophosphine, e.g. a tria- 5] Oct. 23, 1973 rylphosphine, with an organoazide such as an arylazide are radiation-sensitive and can be imagewise exposed to activating rays to yield a'species that can react with a dye-forming coupler to form 'an image dye, e.g. an azo dye. Optionally, such compositions can include a polymeric binder and/or a dye-forming coupler. In another aspect, image-forming compositions are presented which include the organoazide and a precursor to the triorganophosphine, a phosphonium salt for example, that yields triorganophosphine on treatment with base. With such an embodiment, the composition is relatively light-insensitive prior to alkaline treatment which activates the composition by forming the phosphine-azide complex in situ, and shelf life is desirably extended. When these compositions are present on a support, photographic or imageforming elements are formed. Once the azidephosphine complex is present in a composition or element of this invention, imagewise exposure to activating rays for the complex and subsequent or concomitant treatment with a dye-forming coupler or the like produces a photographic image in exposed regions, i.e. a negative image of the original exposure. If a leuco compound, dye forming coupler, etc., is present in the composition, then a visible image generally forms on exposure. After production of the image, it can be stabilized by overall heating. In certain cases, heat fixation also produces intensification of a low density or substantially latent photographic image. If desired, positive images can be formed by thermophotographic'means. Once the phosphineazide complex is present in the composition, imagewise exposure to heat desensitizes the complex in heated regions and a subsequent overall exposure to activating rays for the complex produces either a visible or an intensifiable photographic image. No heat fixation is required, but image intensification can be accomplished by heat. Lithographic printing surfaces can be prepared when a hydrophilic polymeric azide is used to form the phosphine azide complex or when hydrophilic polymeric couplers are used to form the dye image.

14 Claims, No Drawings BACKGROUND OF THE INVENTION 1'. Field of the Invention This invention relates to photography and particularly to new photographic and image-forming compositions and elements that can be negative-working, as well as to photographic processes that are useful in producing stable images thatcan be formed in thesubstantial absence of moisture or noxious developing agents.

2. Description of the Prior Art 1 Photographic compositions designed for dry or substantially dry processing are known. Widely used such formulations are two-component diazotype compositions that include a diazonium salt and a coupler that, under alkaline conditions, can react with the diazonium salt toform an azo dye. A broad description of diazotype elements'appears in Kosar, Light-Sensitive Systems, John Wiley & Sons, Inc., New York (1965), especially at Chapter 6. On exposure to light, the lightsensitive diazonium salt is destroyed and subsequent treatment with an alkaline developer like ammonia promotes a dye-forming reactionin-unexposed areas to produce a positive reproduction of an original line transparency or the like. Diazotype compositions, however, have certain disadvantages in that they tend to suffer background printup on storage. This tendency can be diminshed by inclusion of an acidic pre-coupling inhibitor, but the addition of such a material slows developr nent rate since the inhibitor must be neutralized before coupling can occur. Additionally, well known developing agents like ammonia are generally either toxic and/or noxious.

Another type of diazotype photographic element uses diazosulfonateswhich, on exposure to light, form diazonium salts that can couple in the normal fashion. These elements are negative-working since they produce imagedye in regions of exposure. However, they suffer the disadvantage that image stabilization usually requires afwashout step to remove remaining sensitive components. v I

Still another well-known type of negative-working photgraphic element uses organic azides and dye precursors. See, for example, U.S. Pat. No. 3,062,650. Such elements yield a printout image directly on exposure. However, an inconvenient-washout step to remove unreacted components is generally necessary to stabilize background areas against subsequent printout.

The desirability of providing new photographic elements that do not use silver as the light-sensitive agent (it being in short supply) and that produce stable images without substantial moisture, stabilization washes, or noxious or toxic developing agent is widely acknowledged. Additionally, widespread contemporary apprehension relative to organic pollutants and their effect on the environment has stimulated activity designed to inhibit the flow of contaminants into the environment. Such goals are also of deep concern to those skilled in the photographic arts.

Accordingly, it is an object of this invention to provide new photographic compositions.

It is another object of this invention to provide novel photographic compositions including a radiation sensitive complex of a triorganophosphine with an organoazide.

Still another object of the present invention is to provide new image forming compositions that include an organoazide and a triorganophosphine precursor.

Yet an additional object of the instant invention is to provide novel photographic and image-forming elements'that include the present photographic and image-forming compositions.

Another object of this invention is to provide new photographic processes for preparing stable images.

An additional object of this invention is to provide novel photographic processes for preparing stable images by means of light and heat in the substantial absence of moisture.

Still another object of this invention is to provide new thermophotographic processes for preparing stable images.

STATEMENT OF THE INVENTION The objects of this invention are accomplished, with radiation-sensitive phosphine-azide complexes. In one aspect, the invention relates to new photographic compositions that include a radiation-sensitive complex of a triorganophosphine with an organoazide. In another aspect, the present invention includes novel imageforming compositions containing suitable precursors to the light-sensitive complex and from which the aforementioned complex can be released conveniently. Optionally, such photographic and image-forming compositions can include a dye precursor, e.g. a dye-forming coupler.

The photographic compositions yield an image directly on exposure to activating radiation for the complex. No external processing agents are required. The background regions can then be stabilized against printup by simple heat fixation. In certain cases, this heating step also produces an intensification of the image. As used herein, the term photographic image refers to visible and latent photographic images. The image-forming compositions can be exposed and developed with similar convenience, but require liberation of the radiation-sensitive complex from the precursors prior to exposure. This can be done, for example, by contacting the image-forming composition with base. Additionally, if a particular photographic or imageforming composition or element does'not contain a coupler, exposure is advantageously followed by treatment with a coupler solution. If desired, positive images can be prepared by thermophotographic means, using an imagewise thermal exposure followed by an overall exposure to activating radiation for the complex (i.e. radiation to which the phosphineazide complex is sensitive). Heat fixation is not required but heating can be used to effect image intensification if desired. Additionally, where the azide of the complex is a polymeric azide or where the coupler is a polymeric coupler, lithographic surfaces can be prepared.

DESCRIPTION OF PREFERRED EMBODIMENT(S) In accordance with the present invention, there are presented new photographic compositions including radiation-sensitive complexes of a triorganophosphine with an organoazide. As used herein, the term radiation sensitive describes sensitivity to electromagnetic rays including X-rays, ultraviolet rays, visible light and the like. The phosphine-azide complexes described herein are chemical complexes that, on exposure to activating rays for the complex, yield a species that can react with a coupler to form an image dye.

A wide variety of triorganophosphines (i.e. phosphines having three organic chemical substituent groups) are useful in forming radiation-sensitive complexes of the present type. In general, any triorganophosphine that will form such a complex with an or ganoazide is useful. Determination of such utility can be accomplished conveniently by simple screening. For example, any triorganophosphine can be codissolved with an organoazide of the types recited elsewhere herein (i.e. p-morpholinophenylazide and/or 4- azidobenzenesulfonamide) usually in equivalent molar quantities or with a slight excess of phosphine and with a B-naphthol dye-forming coupler, e.g. 2-naphthol, 2,3- naphthalenediol, etc., to form a solution which can be coated onto a support, dried in a layer and thereafter exposed to activating radiation (i.e. rays to which the complex is sensitive) to form a photographic image which is visible or is intensifiable to a visible image. If this image, when visible, is different in color and/or intensity'from the photographic image that is formed when a similar preparation, but containing only the azide and coupler, (i.e. without the phosphine) is dissolved, coated, dried and exposed in the same manner, then the particular triorganophosphine is useful herein. Although, dye formation can occur on exposure, as mentioned elsewhere herein, subsequent overall heating may be necessary to register to intensify a substantially latent image for convenient viewing.

f the wide range of triorganophosphines that are useful herein, particularly useful materials include those having the formula wherein:

R represents one of either an alkyl group or an aryl group, and R additionally represents a group having the formula wherein:

n represents a positive integer having a value of from 1 to about 18 and each of R and R is as previously defined.

As used herein the term alkyl group includes substituted or unsubstituted, straight and branched chain alkyl groups having-from l to about 8 carbon atoms in the aliphatic chain used as a basis for establishing the nomenclature for such group. Representative alkyl groups include, for example methyl groups, ethyl groups, 2-chloroethyl groups, n-propyl groups, isopropyl groups, n-butyl groups, tert-butyl groups, pentyl groups, hexyl groups, heptyl groups, n-octyl groups, tert-octyl groups, etc. The term alkoxy group as herein defined, includes alkoxy groups the alkyl moiety of which has from 1 to about 8 carbon atoms and corresponds to the alkyl groups recited immediately hereinaboove. The term lower alkyl group or lower alkoxy group refers to such alkyl or alkoxy groups having from 1 to 4 carbon atoms in the aliphatic chain used as a basis for establishing the chemical nomenclature for any such group.

Aryl group, as herein defined, includes substituted or unsubstituted mono and polycyclic aromatized carbocyclic groups having from 6 to 14 atoms in the nucleus, e.g., phenyl, p-chlorophenyl, 4-methylphenyl, naphthyl, anthryl, etc., with phenyl being preferred.

Especially desirable triorganophosphine compounds include triphenylphosphine tris(3-methylphenyl)phosphine P,P-diphenyl-P-methylphosphine tris(4-methylphenyl)phosphine trimethylphosphine P,P-diphenyl-P-ethoxyphosphine P,P-dimethyl-P-phenylphosphine P-pentafluorophenyl-P,P-diphenylphosphine butyldimethoxyphosphine tris(n-butyl)phosphine tris(dimethylamino)phosphine tris(n-octyl)phosphine tris(diphenylamino)phosphine P-methyl-P,P-diphenylphosphine tris(4-chlorophenyl)phosphine tris(4-methoxyphenyl)phosphine triethoxyphosphine l,2-bis(diphenylphosphino )ethane l ,4-bis(di-n-butylphosphino )butane l ,8-bis(di-4-chlorophenylphosphino )octane According to this invention, at least one triorganophosphine is chemically combined with an organoazide to form radiation-sensitive phosphine-azide complexes. Such complexes form under ambient conditions when the triorganophosphine and organoazide are brought into intimate contact such as by codissolving them in a suitable solvent. As with the triorganophosphine, a wide range of organoazides are useful, and the operability of any particular azide can be established by the convenient procedure outlined hereinabove with respect to the screening of triorganophosphines. In this instance, however, an operator would codissolve the azide in question with a phosphine that is known to operate in the present compositions, elements and-processes, e.g. triphenylphosphine.

Desirable organoazides (i.e. organic azides) include a large variety of radiation-sensitive compounds that have been used heretofore in photographic printout compositions of the type that includes the azide and a dye-former that reacts with the azide upon exposure to activating rays to form a dye in exposed regions. Certain such azides include most of the aryl azides, aminoaryl-azides, and heterocyclyl azides described in U.S. Pat. No. 3,062,650 and U.S. Pat. No. 3,282,693. Azides useful as photosensitizers for polymers are also useful herein. Such photosensitizers can be the same as or different from the azides useful in printout materials and they are described in some detail in Kosar, Light-Sensitive Systems, John Wiley & Sons, lnc., New York (1965) especially at pages 330-336 (including footnotes). Still other descriptions of useful organic azides appear in U.S. Pat. No. 2,940,853, U.S. Pat. No.

3,061,435 and U.S. Pat. No. 3,143,417. With regard to heterocyclylazides, it is preferred that the azido group is not substituted on the heterocyclic ring at a position ortho to ahete'ro ring atom. Other advantageous azides include polymeric azides such as those described in U.S.,Pat. No. 3,002,003 and U.S. Pat. No. 3,096,311.

Particularly useful organoazides include such materials as the following:

4-azidobenzenesulfonamide ethyl 4-azidobenzoate ethyl 2-azidobenzoate glyce'ryl 4-azidobenzoate 3-azidobenzoic acid 4-azidobenzenearsonic acid 4-azidobenzamide I 4-azido-N-methylacetanilide 4-azidobenzophenone 2-(4-azidophenyl)-6-methylbenzothiazole 3-azido-a,a, a-trifluorotoluene 3-azido-4-chloro-a,a,a-trifluorotoluene 4-azidobenzonitrile 3-hydroxypropyl 4-azidobenzoate phenyl 4-azidobenzoate 2-( 3-hydroxynaphthyl )4-azidobenzoate 4-methyl-N-phenyl-4-azidobenzamide N-(2,6-dimethylphenyl)-4-azidobenzarnide 4-azidobenzopiperidide N-( 1-naphthyl)-4-azidobenzamide N-(pentafluorophenyl)-4-azidobenzamide phenyl 4-azidophenylsulfonate 2,4 ,6-trichlorophenyl 4-azidophenylsulfonate N-(4azidophenylsulfonyl)phthalimide 4-azidobenzophthalimide I N-phenyl-N-methyl-4-azidophenylsulfonamide N-(4-azidophenylsulf0nyl)-piperidine N-(2,6-dimethylphenyl)-4-azidophenylsulfonamide N-(4-azidophenylsulfonyl)succinimide N-( 6-azido-2-naphthylsulfonyl)piperidine N-methyl-N-phenyl-2-azidonaphthalene-6 sulfonamide I phenyl -azidonaphthalene-2-sulfonate N-(6-azido-2-naphthylsulfonyl)succinimide N-( 6-'azido -2-naphthylsulfonyl )phthalimide 1-azido-2,4,6-trichlorobenzene 2-azido-3nitrobenzene 4-azidobenzoic acid 3-azidophthalic anhydride 4-azidocinnamic acid 3-azidobenzenesulfonamide 2-azido-9-fluorenone l -azido-5-methoxynaphthalene 2-(4-azidophenyl)-5-phenyloxazole 4-azido-4-chlorochalcone 2-(4-azidophenyl)benzoxazole l-azidonaphthalene 2,-phenyl-5-(4-azidophenyl)oxazole 2-( 4-azidobenzylidene )-3 ,4-dihydro-2H- 1 naphthone 4-azidochalcone N 4-azidobenzylidene )-4-chloroaniline 2-( 4-azidophenyl )benzimidazole l-azido-2,4-dichlorobenzene 2-( 3-azidophenyl )-5-phenyloxazole 4,4'-diazido-3 ,3 '-dimethoxybiphenyl 2-azidophe netole 4-azidophenetole trimethylene bis( 4-azidobenzoate) 6 bis(4-azidophenyl)disulfide 4-azido-3,S-diethoxybenzanilide N-methyl-4-azidoacetanilide 4-azidophenyl sulfide 4-azido-3-nitroanisole N-(3-azidophenylsulfonyl)succinimide 4-azido-3 ,5-dimethoxyphenylmorpholine' 3-azidoquinoline 2-azidocarbazole 2-azidobenzoic acid 4-azidophenoxyacetic acid N-rnethy]-N-octadecyl-4-azidoaniline l-azido-4-bromonaphthalene bis(4-azidophenyl)ether 4-azidoazobenzene N-(4-azidophenyl)-N-methylmorpholinium tetrafluoroborate 4-azido-4-toluenesulfonanilide 4-azidobenzenesulfonic acid 1 -azido-4-methoxynaphthalene 4-azidostyryl l-naphthyl ketone 3-(4-azidophenyl)coumarin l,2,3,4,5 ,6-hexa(4-a2idobenzoxy)hexane 4,4-diazidodibenzalacetone l-azido-2,4,6-tribromobenzene 4-azidoacetanilide 2-azidodiphenyl ether 2,5-bis(4-azidophenyl)oxazole 2-(4-azidophenethyl)-5-phenyloxazole 2-(4-azidophenethyl)benzoxazole 4,4'-diazido-2,2-stilbenedi(N,N-

dibutylsulfonamide) 2,6-di(4-azidobenzal)-4-methylcyclohexanone poly(vinyl acetate-co-4-azidobenzoate) 1-azido-3-cyano-4-methoxybenzene l-azido-3-cyano-4-morpholinobenzene N-(4-azido-2-cyanophenyl)piperidine N-butyl -4-azido-2-cyanoaniline N,N-diethyl-4-azido-2-cyanoaniline N,N-dibutyl-4-azido-2-cyanoaniline N-hydroxyethyl-4-azido-2-cyanoaniline N,N-diethyl-4-azido-2-chloroaniline 4-azidodiphenylamine 4-azido-Z-cyanodiphenylamine 4-azido-2-cyano-4-methoxydiphenylamine 4-azido-2-cyano-4-dimethylaminodiphenylamine l-azido-2-methoxy-4-morpholinobenzene l-azido-3-methoxy-4-morpholinobenzene N-methyl-4-(4-azidophenyl)-2,6-diphenylpyridinium perchlorate N-methyl-4-( 4-azidostyryl)-2,6-diphenylpyridinium perchlorate, and

2,5-bis-(4-azidophenyl) oitadiazole In another aspect of the present invention, the triorganophsophine can be replaced by a percursor for such phosphine to prepare stable image forming compositions. Image-forming compositions and elements of this invention are distinguished from the subject photographic compositions and elements in that the imageforming counterparts do not contain the radiationsensitive phosphine-azide complex as prepared, it being formed therein at a subsequent time as desired. Espe cially desirable phosphine precursors are those which, on chemical treatment, e.g. on treatment with base, yield a triorganophosphine that can form a radiationsensitive complex with an azide such as those described herein. Since these image-forming compositions are not substantially radiation-sensitive prior to liberation of the phosphine, their sensitivity being limited to that of the low speed azide, they enjoy an extremely high storage stability. Once the phosphine is released, such as by means of chemical treatment, the radiationsensitive phosphine-azide complex forms spontaneously in situ and the activated composition can be used to prepare photographic images according to the procedures described herein.

A preferred class of phosphine precursors are phosphonium salts from which the corresponding triorganophosphine is easily released by treatment with base, e.g. fuming with ammonia. A wide range of useful phosphonium salts include those described in a patent application of Reynolds entitled Image-Forming Compositions Including Phosphonium Salts, application Ser. No. 168,395, filed Aug. 2, 1971. Exemplary phosphonium salts useful herein include cyclohexanon-3-yltriphenylphosphonium chloride Z-methylcyclohexanon-B-yltriphenylphosphonium tetrafluoroborate cyclohexanon-3-yltri-p-tolylphosphonium chloride 2-methylcyclohexanon-3-yltri-p-tolylphosphonium perchlorate 2-ethoxycarbonylethyltriphenylphosphonium fluoroborate 2-ethoxycarbonylethyltri-p-tolylphosphonium bromide 3-oxobutyltriphenylphosphonium tetrafluoroborate 4-oxopent-2-yltriphenylphosphonium chloride 3-oxol -phenylbutyltriphenylphosphonium perchlorate 3-oxobutyltri-p-tolylphosphonium chloride 4-oxopent-2-yltri-p-tolylphosphonium bromide 3-oxo-l-phenylbutyltri-p-tolylphosphonium bromide a-benzoylmethylbenzyltriphenylphosphonium tetrafluoroborate a-benzoylmethylbenzyltri-p-tolylphosphonium chloride Another preferred class of phosphine precursors from which triorganophosphine can be released by treatment with base are certain stable transition metal complexes of triorganophosphines. They are described in detail in a patent application of Nelson entitled Image Forming Compositions Including Transition Metal Complexes," application Ser. No. 168,393, filed Aug. 2, 1971.

The photographic and image-forming compositions can, if desired, contain a polymeric carrier vehicle. Advantageous carriers include film-forming, substantially hydrophobic polymers that can be coated using organic solvents, but which are sufficiently permeable to bases including gasses and liquids so as not to restrain either convenient phosphine release from a precursor or image dye development. Especially useful such carrier or binder vehicles include polymers like, for example, cellulosic compounds such as ethyl cellulose, butyl cellulose, as well as cellulose esters like cellulose acetate, cellulose triacetate, cellulose butyrate, cellulose acetate butyrate, etc.; vinyl polymers such as poly(vinyl acetate), poly(vinylidene chloride), poly(vinyl butyral), copolymers of vinyl chloride and vinyl acetate, polystyrenes, poly(methyl methacrylate) homopolymers or copolymers of acrylamides, copolymers of alkylacrylates and acrylic acid, etc., such as poly(N-isopropylacrylamide) poly(diacetone acrylamide) tetracopoly(diacetone acrylamide/N- isopropylacrylamide) copoly(methacrylamide/N-isopropylacrylamide) copoly(N-isopropylacrylamide/ l -vinyl-2- pyrrolidone) copoly(methyl methacrylate/methacrylic acid) copoly(butyl acrylate/acrylic acid) as well as additional polymers such as poly(phenylene oxides), tel-polymers of ethylene glycol, isophthalic acid and terephthalic acid, terpolymers of pcyclohexanedicarboxylic acid, isophthalic acid and cyclohexylenebismethanol, copolymers of pcyclohexanedicarboxylic acid and 2,2,4,4- tetramethylcyclobutane-l,3-diol, and additional polymers such as, for example, the condensation product of epichlorohydrin and bisphenol-A.

The photographic or image-forming compositions of this invention can also include a dye-forming coupler which, it is theorized, reacts with a photolytic product of the phosphine-azide complex to form a dye in exposed regions. If used, the coupler is usually present in a molar amount substantially equivalent to the amount of phosphine-azide complex, or in a slight excess, e.g. 5-l0% molar, to insure maximum dye formation.

Couplers that are advantageous herein include couplers of the type used in two-component diazotype compositions. Such couplers are described in the literature, for example in Kosar Light-Sensitive Systems, John Wiley & Sons, New York (1965), especially at pp 220-240. Especially desirable couplers are recited in US. Pat. No. 3,573,052, especially at column 6, line l7 to column 7, line 20. Representative couplers of this type include 2,3-naphthalene diol 2-hydroxy-3-naphthanilide 2-hydroxy-2-methyl-3-naphthanilide 2-hydroxy-2,4'-dimethoxy-5 -chloro-3- naphthanilide 2-hydroxy-2',4-dimethoxy-3-naphthanilide 2-hydroxy-2',5-dimethoxy-4-chloro-3- naphthanilide 2-hydroxy-l '-naphthyl-3-naphthanilide 2-hydroxy-2'-naphthyl-3-naphthanilide 2-hydroxy-4-chloro-3-napthanilide 2-hyd roxy-3-naphthanilide 2-hydroxy-2,5-dimethoxy-3-naphthanilide 2-hydroxy-2,4-dimethyl-3-naphthanilide 1-hydroxy-2-naphthamide N-methyll -hydroxy-2-naphthamide N-butyll -hydroxy-2-naphthamide N-octadecyll -hydroxy-2-naphthamide N-phenyl-1-hydroxy-2-naphthamide N-methyl-N-phenyll -hydroxy-2-naphthamide N-( Z-tetradecyloxyphenyl l -hydroxy-2- naphthamide N-[4-( 2,4-di-tert-amylphenoxy)butyl]- l -hydroxy-2- naphthamide l-hydroxy-2-naphthopiperidide N-( 3 ,S-dicarboxyphenyl )-N-ethyll -hydroxy-2- naphthamide N,N-dibenzyl- 1 -hydroxy-2-naphthamide N-( 2-chlorophenyl l -hydroxy-2-naphthamide N-( 4-methoxyphenyl l -hydroxy-2-naphthamide l-hydroxy-2-naphthopiperizide l,3-bis( l-hydroxy-2-naphthamido)benzene '2-acetamido-S-methylphenol 2-acetamido-5-pentadecylphenol 9 2-butyramido-5-methylphenol 2-(2,4-di-tert-amylphenoxyacetamido)-5- methylphenol 2-benzamido-5-methylphenol Still other useful couplers include those which contain a reactive methylene or methine group, such as those described in US. Pat. No. 3,062,650, especially at column 4, line 8 to column 4, line 27. This type of coupler, e.g. 3-methyl-l-phenyl-S-pyrazolone, is particularly useful when the organoazide has an amino group substituted on the organic residue, as in the case of an aminoarylazide. Preferably, such aminoarylazides are 4-amino-l-azidobenzejne compounds-or derivatives.

The photographic compositions of this invention are conveniently prepared, for example, by codissolving at least one triorganophosphine and at least one organoazide. Desirable solvents include a wide range of organic media such as methyl ethyl ketone, methylene chloride, acetone, lower alkanols, dichloroethane, tetrahydrofuran, toluene, etc., either alone or in combination. In the solution, the ratio of phosphine to azide can be varied widely, but it is preferred that the phosphine be included in a slight molar excess, e.g. from 5-l0%, to insure that substantially all azide is complexed. Without substantially complete azide complexing background stabilization is impaired. Image-forming compositions are prepared in a like manner except that the phosphine precursor is included in lieu of the triorganophosphine.

Photographic and image-forming elements utilizing the photographic and image-forming compositions of this invention are conveniently prepared by coating such compositionsonto a support material. Advantageous support materials include conventional photographic film base materials like cellulose esters such as cellulose acetate, cellulose triacetate, cellulose acetate butyrate, etc'.; poly-a-olefins typically having from 2 to carbon atoms like polyethylene, polypropylene, and polystyrene; polyesters such as poly(ethylene terephthalate); polycarbonates as well as metals such as zinc and aluminum and paper including polyethylene and polypropylene coated papers. Other support materials that are suitably used-herein are, known in the art.

Coating is typically by solvent coating means,'since it offers the potential for rapid, convenient, continuous operation. Coating is effected by first dissolving components of the photographic or image-forming composition in a suitable solvent, such as those described herein, along with a matrix polymer if desired. Exemplary matrix polymers are described hereinabove. The coating solution conventionally contains from about 5 to about 20 weight percent solids, and preferably from about 8 to about percent solids. In that solution, if a matrix polymer is utilized, the image-forming components are typically included in an amount of from about to about 50 parts by weight per 100 parts of polymeric binder, with concentrations in the range of from about to about 45 parts per 100 parts of matrix polymer being preferred. Wider variations are possible where desired, but the above-mentioned ratios are typical for most conventional preparations. After coating by such means as immersion, whirler coating, brushing, doctor blade coating, hopper coating or the like, typically at a wet thickness of from about 0.001 inches to about 0.02 inches, the coated material is dried to prepare a composite photographic or image-forming element of this invention. The subject photographic elements are radiation-sensitive and, without further treatment, can be imagewise exposed to activating rays for purposes of image preparation. The selection of appropriate exposing rays will depend on the spectral response for the particular phosphine-azide complex. Characterization of appropriate exposing rays can be readily determined by preparation of wedge spectro grams for the phosphine-azide complex in question. Generally, however, the region of spectral response will include ultraviolet and other actinic rays so that exposure by means of a mercury arc lamp, which is rich in U.V. rays, or a similar exposure source is appropriate. Numerous diazo copiers and other commercially available photocopying apparatus incorporate exposure stations which include radiation sources emitting in the U.V. As a general rule these are quite satisfactory for exposing compositions and elements of this invention.

It is noted that the radiation-sensitivity of the phos phine-azide complexes described herein should not be equated to the known sensitivity of aryl azides such as those used in vesicular photography or other photographic systems. Such compounds are known to exhibit low photoreactivity, whereas the radiation-sensitive complexes of this invention exhibit a relative photographic speed about ten times that of a comparable non-complexed azide.

As noted herein, the subject image-forming compositions and elements are activated to yield a triorganophosphine and form the phosphine-azide complex by chemical treatment including treatment with base. Generally, any of the bases useful in initiating coupling in diazotype reproduction media, e.g. ammonia, organic amines and other organic nitrogen bases, are suitable herein to release the phosphine from its precursor. A range of such bases is described in Kosar, cited hereinabove, as well as in the patent literature, for example US. Pat. No. 3,578,452, Canadian Pat. No. 772,109, etc. It is preferred that the base have a pH of at least about 8 so that activation is obtained rapidly. Treatment can be accomplished by immersion in a solution of the base, by fuming with vapors of the base, etc.

When the sensitive phosphine-azide complex of a photographic composition or element or suitably activated image-forming composition or element is exposed to activating rays, and if a coupler is included in the composition or element that is so exposed, an image forms in exposed regions. Usually, this is a readily visible dye image which can vary in optical density depending on the particular formulation. In certain cases, the image may be a latent image that is not easily visible or is not visible at all. It is theorized that the dyeforming reaction is promoted by the imagewise release of hydroxyl ions and ammonium hydroxide on exposure of the phosphine-azide complex. It is theorized further that this liberation is due to reaction of a phosphinimine anion that is formed on exposure with water that is inherently present in the composition or element.

Subsequent to an image-defining exposure, the composition or element is preferably heated to a temperature sufficient to stabilize non-image regions against printup (i.e. to stabilize the photographic image). It is theorized that on heating, the phosphine-azide complex rearranges to form a stable, substantially colorless phosphinimine. Where the image exposure either is of low optical density or is a latent image, the heat stabilization treatment simultaneously effects an image intensification such that it is readily viewable by eye. Stabilization heating is generally accomplished at temperatures of at least about 60 C, with temperatures up to about 130 C being useful for most situations. It will be recognized that the support or any components should not be deliteriously affected by heating, but higher temperatures require shorter fixation times. The dureation of the heat fixing step is variable, depending on factors like fixation temperature, etc. Usually, times of from about seconds to 2 minutes are sufficient. Heating can be carried out conveniently, such as by contact with a suitably heated surface, insertion into a heated chamber or the like.

In cases where no coupler is present in the composition or element, exposure of the phosphine-azide complex is desirably followed by treatment of the composition or element with one or more couplers of the types described herein to promote image formation. A dense dye image will then form spontaneously, or an intensifiable image of the type noted herein will result. As an example of useful treatment methods, a coupler solution can be contacted against the composition or element by such means as immersing the composition or element therein, swabbing or spraying the solution over the composition or element, or by a similar means. After such treatment, the composition or element can be washed and/or dried or drying can be accomplished simultaneously with heat stabilization.

In one embodiment of the invention, a base can be included in an image-forming composition or element, in lieu of the phosphine precursor. Useful bases include, for example, N,N,N',N'-tetramethylethylene diamine, as well as a wide variety of other organic amines and nitrogen containing organic compounds. Activation to form the phosphine-azide complex is then accomplished by treatment with a phosphine precursor such as those described herein. Treatment is easily carried out by using a solution of the precursor according to methods like those discussed previously with reference to coupler treatment.

in yet another embodiment of this invention, an image-forming composition that includes a phosphine precursor, a radiation-sensitiveazide of the type described in U.S. Pat. No. 3,062,650 wherein an amino group is present thereon, e.g. a p-disubstitutedaminophenylazide, and a coupler that is reactive with such an azide, multiple images such as two-color dye images can be prepared as follows: The composition is given a first imagewise exposure with activating radiation for the azide, i.e., radiation to which the azide is sensitive. A visible dye image forms on exposure. The composition is then activated by chemical treatment such as by contact with base (e.g. by fuming with ammonia vapor) to release triorganophosphine from the precursor and form the phosphine-azide complex and thereafter is given a second image-wise exposure with activating radiation for the complex, i.e., radiation to which the complex is sensitive. Since the complex is a different chemical species from the azide, it can have a different spectral absorption envelope. Accordingly, each exposure may require the use of a different radiation source, although ultraviolet rays will generally suffice. On the second exposure, an image forms in exposed regions. It will be appreciated that this second dye image may, in certain cases, be intensifiable as discussed herein. This second image, when visible, is preferably of a different color from the image formed on the first exposure. Heat stabilization is then ccomplished, and this also effects image intensification of the second dye image if it is of a low optical density. If the concentration of azide is sufficient, and the first exposure is not so intense that all azide is photolized in regions of exposure, then remaining azide in such regions will complex with the phosphine on activation with base and the second exposure will produce a second dye in areas that are common to each exposure.

As discussed previously, the compositions and elements of this invention are useful in preparing negative images, i.e. images corresponding to regions of irradiation. They can also be processed by thermophotographic techniques to prepare positive images, i.e. images corresponding to non-irradiated regions. A photographic composition or element, or an image-forming composition or element which has been activated to form a phosphine-azide complex therein, is given an imagewise thermal exposure to stabilize such regions against printup. Thereafter, it is overall exposed to activating radiation for the complex to prepare a visible or intensifiable dye image. If no coupler is present in the element, image devlopment will also include treatment with a coupler solution as described elsewhere herein.

In still another embodiment of this invention, lithographic surfaces are prepared in exposed regions when the azide used is a hydrophilic polymeric azide like those described in U.S. Pat. No. 3,002,003 and other references cited therein. Lithographic surfaces can also be prepared when the coupler is a hydrophilic, polymeric coupler such as a polymeric pyrazolone. Desirably, the azide used with the polymeric coupler is a his azide. After exposure and subsequent process steps as described herein, the developed surface is wet with water which is accepted in unexposed areas. Greasy printing inks are transferable from exposed regions which comprise the printing surface.

The following examples are included for a further understanding of the invention.

EXAMPLE I A solution of l-azido-4-morpholinobenzene (0.2 g), 4-methoxy-l-naphthol (0.2 g) and triphenylphosphine (0.25 g) is prepared in 20 ml of a 4% solution of poly(- vinyl butyral) in methyl ethyl ketone. This solution is whirl coated on aluminum and exposed imagewise to the ultraviolet rich rays of a 250 Watt high pressure mercury vapor lamp, yielding a purple printout image. The unexposed areas are then stabilized by heating the plates to C for l minute.

EXAMPLE 2 A solution of 4-azidobenzenesulfonamide (0.2 g), 2,3-naphthalenediol (0.2 g), and cyclohexanon-El-yltriphenylphosphonium chloride 1.0 g) in 30 ml of a 10% cellulose acetate butyrate solution in methylene chloride is doctor blade coated at a thickness of 0.006 inch on poly(ethylene terephthalate) support and dried. The resultant element is then exposed to NH vapor. Thereafter, the image-forming element is exposed through a silver negative at 20 ft./minute in the exposing unit of a Model 22,000 Ozalid machine marketed by Ozalid Corporation. The machine contains a L200 Watt high pressure mercury vapor lamp as an exposure source. The resulting yellow-orange image is heated at C for 10 seconds to produce a stable, fixed print.

EXAMPLE 3 A solution of l-azido-4-(2-benzimidazolyl)benzene (0.05 .g) triphenylphosphine (0.10 g) and 4- methoxynaphthol (0.05 g) is poured onto a filter paper and dried. The paper is then exposed imagewise to a 500 Watt infrared lamp for 10 seconds through and in contact with a silver negative. The entire sheet is then irradiated with-U.V. light to produce a dye image in the thermally unexposed areas.

I EXAMPLE 4 A solution of p-morpholinophenyl azide (0.15 g), a coupler, 2,4-diehloro-6-(2,4- dipentylphenoxyacetamido)-3-methyl-phenol (0.2 g) and P-( 2-acetyl-1 -phenylethyl )-P,P,P-triphenylphosphonium tetrafluoroborate (0.8 g) is prepared in 15 ml of acetone. This is added to 15 ml of a 1-0 percent solution of celluloseacetate butyrate in dichloroethane and the mixture is doctor blade coated on poly(ethylene terephthalate) film support at a wet thickness of 0.006 inch. The resulting image-forming element is first exposed on a Model 22,000 Ozalid machine at ft./minute to form a blue dye image in exposed areas. The element is then contacted with moist ammonia vapor at 50 C for 10 seconds to liberate phosphine from the phosphonium salt precursor, and re-exposed in the O2- alid copier at ft./minute to produce an orange dye image in the newly exposed areas. The background regions are stabilized by heating to 1 10 C for 5 seconds, producing a pale pink background. Other-useful bases that can be used to liberate the phosphine and activate the composition include aqueous solutions of an organic base such as those described in US. Pat. No.

Using techniques asdescribed in Example 4, but coating a radiation-sensitive layer on each side of a transparent support which has a substantially colorless U.V. absorber contained in the support or in a separate layer or otherwise positioned between the support and one 'of the radiation-sensitive layers, it is possible'to form, four-color elements that can'be viewed conveniently. Processing is as in Example 4, except that the appropriate exposures are desirably doubled to expose separately the radiation-sensitive materials present on each side of the support.

EXAMPLE 5 A coating solution is prepared from 0.15 g of 4-4- bis(azido)-3,3'-dimethoxybiphenyl, 0.3 g of 2,3- naphthalenediol, 10 drops of N,N,N,N-tetramethylethylenediamine, 3 drops of formaldehyde, 15 ml of an 8.8 percent solution of copoly(N-isopropylacrylamideacrylamide-2-acetoacetoxyethyl methacrylate) (Mole ratio 2:7:0.5) in a 1:1 by volume mixture of acetone and ethanol, and 15 ml of acetone. The mixture is doctor blade coated on poly(ethylene terephthalate) film support at a wet thickness of 0.00.6 inch and dried. A portion of the resultant element is dipped in a 10 percent solution of I cyclohexanon-3-yltriphenylphosphonium chloride in water. The coating dipped portion is then dried, exposed at a setting of 3 ona Model 70 Bruning Copier, marketed by the Charles Bruning Division, Addressograph Multigrapl'l Corporation, and heated at 1 10 C to stabilize the wine-colored dye image. The portion of the coating not dipped into the phosphonium salt solution produces no image at all when exposed and heated in a like manner.

The invention has been described in detail with particular reference to certain preferred "embodiments thereof, but it willbe understood that variations and modifications can be effected within" the spirit and scope of the invention. 1

There is claimed:

l. A photographic composition comprisingan azo dye-forming coupler, and a radiation-sensitive complex of an organoazide with a triorganophosphine, which phosphine, when codissolv ed with pmorpholinophenylazide and/or 4-azidobenzenesulfonamide and a [3 -naphthol azo-dyeforming coupler, forms a composition which can be dried in a layer and imagewise exposed to activating radiation to form a photographic image that, when visible, is different in color and/or intensity from the photgraphic image that is formed when a similar composition, but without the triorganophosphine, is dissolved, dried and exposed in the same manner, said organoazide being a radiation-sensitive aryl or heterocyclyl azide and the. phosphorus atom of said trioganophosphine is tertiary and directly linked to three carbon atoms.

2. A photographic composition as described in claim v 1 wherein the organoazide is an arylazide.

3. A photographic composition as described in claim 1 wherein the organoazide is a heterocyclyl azide.

4. A photographic composition as described in claim 2 and further comprising a polymeric binder material.

5. A photographic element comprising a support having thereon a photographic composition as described in claim 1.

6.-A photographic element comprising a support having thereon a photographic composition as described in claim 1.

7. An image-forming element as described in claim 6 wherein the organoazide is an aryl azide.

8. An image-forming element as described in claim 6 wherein-the organoazide is a heterocyclyl azide.

9.A photographic composition comprising a radiation-sensitive complex of an organoazide with a triorganophosphine having the formula wherein each R, R and R independently represents one of an alkyl group, an alkoxy group, an aryl group, or an amino group having the formula wherein R represents either an alkyl group or an aryl group, and R additionally represents a group having the formula wherein n represents a positive integer having a value of from 1 to about 18 and each R and R is as previously defined, and an azo dye-forming coupler, said organoazide being a radiation-sensitive aryl or heterocyclyl azide.

10. A photographic composition as described in claim 9 and further comprising a polymeric binder material.

1 l. A photographic composition as described in claim 9 wherein the phosphine is a triarylphosphine or a trialkyl-phosphine.

12. A photographic composition as described in claim 9 wherein the phosphine is triphenylphosphine, tris(3-methylphenyl)phosphine, tris(4-methylphenyl)phosphine, tris(4-chlorophenyl)phosphine, tris(4-methoxyphenyl)phosphine, P-pentafluorophenyl-P,P-diphenylphosphine,

scribed in claim 9.

I I I i i TEA?" UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,767,, Lo9 Dated October 23, 1973 Inventor(s) Patrick Grisdale and Bruce Babb It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

r- Title page, under heading "UNITED STATES PATENTS",

line 1, "Sogura" should read ---Sagura-. j

Column 1, line 45, "photgraphic" should read ---photographic--.

. Column 3,. line 29, "to" (second occurrence) should read ---or---.

Column 3, line 39, "R should read "-13 Column L, lines 3-4, "hereinaboove' should read --hereinabove- Column 5, line 32, that part of the formula reading iazidophenylsulfonylw should read- L-azidophenylsulfonyl)-.

Column 5, line #6, that part of the formula reading "3nitrobenzene" should read 3-nitrobenzene Column 6, lines 55-56, "triorganophsophine" should read ---triorganophosphine--.

Column 10, line 65, after "image" ---aftershould be inserted.

} Column 12, lines 1-2 "ccomplished" should read -accomplished---.

Column 12, line E L, "devlopment" shouldread ---development---,

Column 1 L, line 32, "2" should read -'l--.

Column l t, line 67, after "each", --of-- should be inserted. y

Signed and sealed this 9th day of July 1974.

(SEAL) Attest:

MCCOY M. GIBSON, JR. I C. MARSHALL DANN Attesting Officer Commissioner of Patents 

2. A photographic composition as described in claim 1 wherein the organoazide is an arylazide.
 3. A photographic composition as described in claim 1 wherein the organoazide is a heterocyclyl azide.
 4. A photographic composition as described in claim 2 and further comprising a polymeric binder material.
 5. A photographic element comprising a support having thereon a photographic composition as described in claim
 1. 6. A photographic element comprising a support having thereon a photographic composition as described in claim
 1. 7. An image-forming element as described in claim 6 wherein the organoazide is an aryl azide.
 8. An image-forming element as described in claim 6 wherein the organoazide is a heterocyclyl azide.
 9. A photographic composition comprising a radiation-sensitive complex of an organoazide with a triorganophosphine having the formula
 10. A photographic composition as described in claim 9 and further comprising a polymeric binder material.
 11. A photographic composition as described in claim 9 wherein the phosphine is a triarylphosphine or a trialkyl-phosphine.
 12. A photographic composition as described in claim 9 wherein the phosphine is triphenylphosphine, tris(3-methylphenyl)phosphine, tris(4-methylphenyl)phosphine, tris(4-chlorophenyl)phosphine, tris(4-methoxyphenyl)phosphine, P-pentafluorophenyl-P,P-diphenylphosphine, P-methyl-P,P-diphenylphosphine, tris(n-butyl)phosphine, tris(n-octyl)phosphine, triethoxyphosphine, or 1,2-bis(diphenylphosphino)ethane
 13. A photographic composition comprising a radiation-sensitive complex of triphenylphosphine with either 1-azido-4-(2-benzimidazolyl)benzene, 4-azidobenzenesulfonamide, p-morpholinophenylazide, N-(4-azidophenylsulfonyl)succinimide or 2-phenyl-5-(4-azidophenyl)oxazole and an azo dye-forming coupler.
 14. A photographic element comprising a support having thereon a photographic composition as described in claim
 9. 